1. Field of the Invention
The present invention relates to a system and method for three-dimensional interaction based on gaze. In particular, the present invention relates to a system and method of using the image of the user's eyes to search for the point on a three-dimensional display screen that the user gazes on.
2. Background of the Invention
The eye gaze tracking technique and eye gaze direction detecting technique have been in the spotlight for new user input in the field of human computer interaction (HCl) and have been developed to assist the disabled use a computer. A person's gaze reflects one's specific interests or changes in body conditions. There has been considerable research on developing attentive user interface (AUI) and safety systems for preventing drowsy driving by utilizing the gaze tracking technique.
Traditionally, a number of methods have been used for tracking one's gaze on a two dimensional screen. For example, an electrooculography (EOG) method can be used where an electrode is put near an eye to track the gaze. Other methods include: monitoring the brightness of a pupil which changes according to the position of the light source; monitoring the point to which the light source is reflected from the cornea; utilizing the phenomena occurring when light from the light source passes through the different layers of eye having different refraction; and the search coil method that utilizes contact lenses. In addition, information regarding a user's head movement, obtained by using a magnetic sensor, and information regarding the center points of the irises and the pupils, obtained by using a camera, have been traditionally used to understand the relationship between the head and eyes and track the gaze. Alternatively, analog methods have also been used to predict one's gaze by monitoring the light variation due to the change in position of a light receiving device and the gaze and utilizing the light receiving device which receives light from a light emitting device and light which is reflected from the eye.
The conventional two-dimensional gaze detection methods mentioned above required monitoring the gaze while the user's head is secured (because of the lack of information on the position of the user's head) or using a separate device for detecting the position of the user's head, and were also not as accurate due to the limitations of the two-dimensional technique. Furthermore, the conventional gaze tracking devices were not suitable for mass production and very expensive and, as a result, have only been used as an input apparatus for the disabled.
There have been reports of using a head tracker or a stereo camera to find the three-dimensional position of the actual user's and then extracting the three-dimensional gaze vector; however, this method has the disadvantage that the user cannot move his/her head freely. The conventional model-based three-dimensional interaction method, which tracks the user's gaze on the basis of feature points of the user's face and the eyes that have been extracted, does not require the attachment of a separate device for detecting interaction, and allows some movement of the head but has the disadvantage that the entire face of the user needs to be captured within the camera's field of view (FOV).